Independent throttle optimization in locomotive consist systems

ABSTRACT

The present disclosure provides systems and methods for reducing the total cost of fuel consumed by a locomotives, particularly a locomotive consist including dual fuel locomotives. The systems and methods include generating an alternative throttle settings with the goal of consuming the highest ratio of low cost fuel over high cost fuel instead of only a focus on consuming the least amount of one fuel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application incorporates by reference and claims priority to U.S. Provisional Application 61/833,429 filed on Jun. 10, 2013.

BACKGROUND OF THE INVENTION

The present subject matter relates generally to the railroad field and more particularly to devices, systems and methods for reducing the total cost of fuel consumed by a locomotives, particularly a locomotive consist including dual fuel locomotives.

A locomotive consist is a group of locomotives physically coupled together and configured to act as a single unit from the controls of a single locomotive in the consist. In the U.S., the operation of multiple locomotives in this manner is often referred to as multiple unit, or “MU”, operation. In this mode the throttle setting (also referred to as the throttle notch) in the lead locomotive, which may not be the first locomotive in the consist, controls the throttle setting or notch in all locomotives in the consist. A locomotive throttle typically has eight notches and an idle position. Thus, for example, in prior systems, if an operator in a lead locomotive in an MU consist puts the throttle in notch 5 (approximately 50% power), then every other locomotive in the consist will also operate at a notch 5 throttle setting (it should be noted that the actual throttle may or may not move in each locomotive, but that the control signals supplied to each locomotive power plant will correspond to a notch 5 throttle setting)

It has been recognized that the operation of all locomotives in a consist in the same throttle setting is not always the most fuel-efficient. Several prior art patents have taught ways to optimize the throttle settings between locomotives in a consist to achieve the same requested total power at a lower fuel consumption rate.

U.S. Pat. No. 4,344,364 teaches a basic system that uses an interface control box in each locomotive of a consist to communicate with each other, calculate the optimum alternative throttle settings for each locomotive, and implement these alternative throttle settings. Hereinafter the interface control box with its alternate throttle setting concept will be referred to as a locomotive throttle optimizer (LTO).

U.S. Pat. No. 7,618,011 is directed to a consist manager system that performs a similar function, and will even modulate the throttle settings on trailing locomotives that don't have the consist manager equipment installed. The important difference is that this type of LTO system requires frequent operator interaction where the train crew must manually input into the lead locomotive's control system the makeup of the consist every time the consist locomotive makeup is changed.

EMD has publically advertised as an option on its newer locomotives a Smart Consist system that appears to perform similar to U.S. Pat. No. 4,344,364. An LTO option is also advertised as an optional feature for its aftermarket EM2000 control system for older locomotives being rebuilt and upgraded.

U.S. Pat. No. 8,095,253 by Invensys teaches a more advanced system than U.S. Pat. No. 4,344,364. This system incorporates more information in an initialization communication string from each LTO to the other LTO's in the consist. This additional information includes a power and efficiency table for the particular locomotive that the LTO is installed on. This allows the upgrading of the power and efficiency information in one locomotive without having to upgrade the data files in the other LTO systems in the locomotive fleet. The entirety of U.S. Pat. No. 8,095,253 is hereby incorporated by reference.

Prior to U.S. Pat. No. 8,095,253 Invensys offered for sale and published an operating manual for an LTO system in which each LTO would have an installed data base of all the possible locomotives in the fleet that it could be connected to. When an LTO is installed in a locomotive, the box is configured to know which type of locomotive it is installed into by configuring some switches internal to the LTO. With 8 DIP switches an LTO can be installed on 256 different locomotive configurations. Upon initialization a typical LTO will broadcast its serial number and the locomotive configuration that it is attached to. Among the LTO's, one unit is typically determined to be the master LTO and the other LTO's become slave LTO's. Currently the master LTO is determined by serial number, with the highest serial number becoming the master LTO. It was the master LTO that performed the calculations and instructed each slave LTO what throttle setting it would operate at.

The improvement of U.S. Pat. No. 8,095,253 is not needed if the internal LTO system programming is revised slightly. As part of the initialization string, each interface unit can also broadcast the revision level or date of its latest software and database update. The LTO with the latest revision should become the master LTO and will have the latest list of locomotive configurations and their corresponding power and efficiency tables. If multiple LTO's have the latest revision level, then the master LTO could be selected from those LTO's by the highest serial number or some other secondary selection method.

Versions of these LTO systems have been developed and demonstrated since 2005 and appear to have been tested by several class 1 railroads but never implemented in quantity. When utilized only with diesel-fueled locomotives it was unlikely to save more than 2% in fuel consumption under typical mainline freight operations. In order for this system to be effective it would have had to be installed in most locomotives of a particular railroads fleet, and it didn't appear to offer a quick enough ROI to be worth this large of an effort for any of the major railroads.

Commercially available LTO systems have calculated alternative throttle settings primarily based on fuel efficiency only. The operating manual for the LTO system offered by Invensys describes an optional input signal channel for locomotive fuel quantity but it is not evident that fuel quantity was used in any calculations.

The most significant limitation of the current LTO systems, is that they currently do not accommodate alternative fuels. As the locomotive industry starts to implement a conversion to natural gas as a substitute for diesel fuel, it is likely that it will take more than 15 years for the industry to fully transition to locomotives fueled only with natural gas. The first few years of this transition is likely to be a transition to dual fuel locomotives that can operate on 100% diesel fuel or a mixture of natural gas and diesel. For the next 5 to 10 years train consists will be mixed between locomotives operated on 100% diesel and locomotives that could operate on either 100% diesel or a mixture of diesel and natural gas. The locomotive fleet will not only have locomotives that have different fuel efficiencies and fuel types, but it will have individual locomotives that can operate on one fuel or both fuels and change between these operating modes while in operation.

When multiple fuels are used throughout a locomotive consist, what is important is not consuming the least amount of fuel, but consuming the least amount of the most expensive fuel. If natural gas fuel is 40% cheaper than diesel fuel for an equivalent amount of energy, it makes sense to focus the power from engines using the natural gas even if that locomotive is 10% less thermally efficient than the locomotive fueled by 100% diesel fuel.

What is desirable is an updated LTO system that can accommodate not just a locomotive that consumes an alternative fuel type but also a dual fuel locomotive that can change what type of fuel it is consuming while in operation. Further this system should require minimal operator input to configure and operate the train. Additions of both new locomotive types and new fuel consumption strategies should only require updating the locomotives equipped with these new improvements and not require updating all LTO units in a locomotive fleet.

BRIEF SUMMARY OF THE INVENTION

The present disclosure provides an independent throttle optimization system in locomotive consists. Various examples of the systems are provided herein.

The system is directed at improving the art of LTO systems to accommodate both alternative fuels and dual fuel locomotives while minimizing the amount of operator input and required LTO unit database updates. Doing this requires incorporating the consumed fuel type or multiple types as additional parameters in the locomotive data that the LTO system stores and uses for calculations. This further requires calculating the alternative throttle settings with the goal of consuming the highest ratio of low cost fuel over high cost fuel instead of only a focus on consuming the least amount of one fuel. This may also require ongoing communication between the LTO systems in a consist of what fuel operating mode each dual fuel locomotive is in. Optionally, incorporating the database revision version or date in each LTO systems initialization string will allow selecting an LTO with the latest database and programming as the master LTO system, thus reducing the need to make fleet wide LTO database updates as new locomotive configurations are added to the fleet.

One embodiment of this LTO as implemented is basically an add-on control box installed into a locomotive with no changes to the locomotive hardware. If the LTO is not functioning, the locomotive will still operate normally. While the LTO does not make any hardware changes, it does make a break into the throttle control signal wires. It will intercept the throttle command signal from the MU cable and either sends that throttle command or a modified throttle command to that locomotives engine control system. Each LTO box works in conjunction with other LTO boxes in the same consist to calculate the optimum alternate throttle settings among the different locomotives in the consist to give the engineer the total power requested with his throttle command, but in the most cost effective or fuel efficient manner possible with some engines at higher throttle notch and some at lower throttle notch.

While the old LTO calculations went by fuel consumption per throttle notch, the new LTO database will have to have at least two fuel tables for each dual fuel locomotive, and an input from the engine control of which fuel type it is running on.

Dual Fuel LTO systems will require a new input signal for dual fuel locomotives indicating what mode the engine is operating in: either dual fuel or 100% diesel. Also it will need a new communications signal among the LTO boxes in a consist so that the master LTO box will know what fuel operating mode the dual fuel locomotives are operating in.

Further the throttle setting optimization calculation will now have two steps, first it will focus the fuel burn on the locomotives that can replace the most diesel fuel with natural gas and maximize the total natural gas consumption, then it will work between the remaining locomotives to consume the least amount of diesel fuel for the remainder of the needed power.

An optional upgrade to the LTO system would be an additional channel or signal to communicate to certain locomotives in the consist that they can be shut down. This may require an output signal to an independent Automatic Engine Start Stop system. This could be triggered after a time period at lower throttle settings when there are multiple dual fuel locomotives and one diesel only locomotive which would not be operated at any throttle setting below notch 7. This feature would save a lot on locomotive emissions and fuel consumption by eliminating the idling of locomotives that will not be used for a long while.

If four GE-9 locomotives are in a consist and the throttle command is notch 5 (50% load) the optimum fuel burn under a prior art diesel fuel only LTO would have been to pick two units to leave at notch 8, and idle the other two. If they were all dual fuel units the calculation is more complicated. Conventional dual fuel locomotives only replace 45% of the diesel with natural gas at high throttle settings, but at notch 5 they replace 70% of the diesel. In this case the calculation to consume the most natural gas would result in all four units operating at notch 5 which would have replaced the most diesel fuel with natural gas thus saving the railroad more money and emitting less emissions. This is in spite of the fact that the most efficient setting on an actual energy basis would have still been to put a pair of locomotives at full throttle and a pair at idle.

Instead of being an add-on box to the locomotive system, the LTO can also be built into the control systems used for converting the locomotive to dual fuel. Most current Energy Conversions Inc. (ECI) conversion systems use a throttle notch relay to manipulate the throttle signal in the same way a prior art U.S. Pat. No. 8,095,253 LTO box did. If there is a malfunction with the dual fuel conversion, the throttle notch relay disconnects the ECI control box from the engine controller and the MU cable throttle signal passes through to the engine control as if the ECI control box is not there. The new embodiment, combine Dual Fuel/LTO controller could have this same throttle notch relay feature built in.

In order to add the LTO system into a dual fuel control system, it may only require the additional programming and hardware so that it communicates with the other LTO systems in the consist across the MU cables.

With the LTO features incorporated into dual fuel conversion systems and the large amount of money that can be saved by focusing the fuel consumption in the natural gas locomotives, there will likely be an add-on LTO added to every diesel powered locomotive that will be operated in consists with dual fuel locomotives.

The present disclosure provides a locomotive consist system comprising at least two locomotives, wherein each locomotive includes a locomotive throttle optimizer (LTO), wherein at least one locomotive includes an alternate fuel type. At least one LTO device is a master LTO device in communication with every other LTO device, wherein the master LTO device includes a controller and a memory coupled to the controller, wherein the memory is configured to store program instructions executable by the controller. The master LTO may be the LTO with the most recent software update.

In response to executing the program instructions, the controller is configured to receive an engineer throttle notch value corresponding to a total power value, and access a database including locomotive information for each locomotive in the consist. The locomotive information includes a fuel type used in the locomotive, a fuel consumption rate corresponding to each of a plurality of throttle notch power levels, and a fuel consumption priority parameter corresponding to each fuel type used in the locomotive. The controller is also configured to generate an alternate throttle setting for each locomotive, wherein the alternate throttle setting includes a selected throttle notch power level. The combination of alternate throttle settings for the at least two locomotives produces a generated total power that is equivalent to the received total power value, wherein the alternate throttle setting is based on the fuel consumption priority parameter. The controller is also configured to communicate the alternate throttle setting to each locomotive.

In an example, the fuel consumption priority parameter includes a fuel consumption cost for each throttle notch power level, wherein the alternate throttle setting is based on minimizing the total fuel cost. In another example, the fuel consumption priority parameter includes a fuel cost, wherein the controller is configured to calculate for each throttle notch power level a fuel consumption cost, wherein the alternate throttle setting is based on minimizing the total fuel cost

In another example, the master LTO device receives a signal from each LTO device indicating an operating mode for the locomotive, wherein the operating mode is selected from a primary fuel mode or a dual fuel mode.

The master LTO device may receive a signal from each LTO device indicating an amount of each fuel type available within the locomotive, wherein at least one locomotive includes an alternate fuel type, wherein the generated alternate throttle setting for each locomotive is based on maximizing an alternative fuel type consumption rate.

The fuel type may be diesel fuel, natural gas, and/or an alternative fuel, or combinations thereof. For example, a fuel type may be a combination of an alternative fuel type and a second fuel type.

In an example, at least one locomotive is a dual fuel locomotive including a first fuel type and a second fuel type. The database includes a plurality of first fuel consumption rates of the first fuel type and a plurality of second fuel consumption rates of a second fuel type, wherein each first consumption rate corresponds to a first fuel power value and a first fuel cost and each second consumption rate correspond to a second fuel power value and a second fuel cost, wherein a total fuel cost is the sum of the first fuel cost and second fuel cost. In such example, the controller generates an alternate throttle setting for the dual fuel locomotive including a selected first fuel consumption rate of the first fuel type and a selected second fuel consumption rate of the second fuel type, wherein the alternate throttle setting for the dual fuel locomotive is based on minimizing the total fuel cost.

In an example, the first fuel cost and second fuel cost are automatically and periodically updated to reflect the market price of the first fuel and second fuel.

The master LTO device may receive a signal from each LTO device indicating an amount of each fuel type available within the locomotive, wherein at least one locomotive includes an alternate fuel type, wherein the generated alternate throttle setting for each locomotive is based on equalizing an alternative fuel type consumption among the locomotives.

The system may include a single fuel locomotive including a single fuel type and a single fuel LTO device in communication with the single fuel locomotive, wherein the single fuel LTO device is in communication with the controller. In such example, the database includes a plurality of single fuel consumption rates for the single fuel type, wherein each single fuel consumption rate corresponds to a single power value and a single fuel cost. In addition, the controller may generate an alternate throttle setting including a selected first fuel consumption rate of the first fuel type, a selected second fuel consumption rate of the second fuel type, and a selected single fuel consumption rate of the single fuel type. The received total power value may be equal to the sum of the first fuel power value of the selected first fuel consumption rate, the second fuel power value of the selected second fuel consumption rate, and the single fuel power value of the selected single fuel consumption rate. A total fuel cost is the sum of the first fuel cost, second fuel cost, and the single fuel cost. The alternate throttle setting is based on minimizing the total fuel cost.

The disclosure also includes a method for producing alternate throttle setting for at least two locomotives in a consist, wherein each locomotive includes a locomotive throttle optimizer (LTO). The method includes receiving an engineer throttle notch value corresponding to a total power value. The method further includes accessing a database including locomotive information for each locomotive in the consist, wherein the information includes a fuel type used in the locomotive, a fuel consumption rate corresponding to each of a plurality of throttle notch power levels, and a fuel consumption priority parameter corresponding to each fuel type used in the locomotive. In addition, the method includes generating an alternate throttle setting for each locomotive, wherein the alternate throttle setting includes a selected throttle notch power level. The combination of alternate throttle settings produces a generated total power that is equivalent to the received total power value, wherein the alternate throttle setting is based on the fuel consumption priority parameter. The method includes communicating the alternate throttle setting to each locomotive.

The fuel consumption priority parameter may include a fuel consumption cost for each throttle notch power level, wherein the alternate throttle setting is based on minimizing the total fuel cost. The fuel consumption priority parameter may include a fuel cost, wherein the method includes calculating for each throttle notch power level a fuel consumption cost, wherein the alternate throttle setting is based on minimizing the total fuel cost.

The method may further include receiving a signal from each LTO device indicating whether each LTO is operating in a primary fuel mode or dual fuel mode. In addition, the method may include receiving a signal from each LTO device indicating the amount of each fuel type available within the locomotive, wherein the generated alternate throttle setting for each locomotive is based on preserving an alternative fuel type.

The fuel type may be diesel fuel, natural gas, an alternative fuel, or combinations thereof. At least one locomotive is a dual fuel locomotive including a first fuel type and a second fuel type, wherein the database includes a plurality of first fuel consumption rates of the first fuel type and a plurality of second fuel consumption rates of a second fuel type. Each first consumption rate corresponds to a first fuel power value and a first fuel cost and each second consumption rate correspond to a second fuel power value and a second fuel cost, wherein a total fuel cost is the sum of the first fuel cost and second fuel cost. The method includes generating an alternate throttle setting for the dual fuel locomotive including a selected first fuel consumption rate of the first fuel type and a selected second fuel consumption rate of the second fuel type, wherein the alternate throttle setting for the dual fuel locomotive is based on minimizing the total fuel cost.

The method may include automatically and periodically updating the first fuel cost and second fuel cost to reflect the market price of the first fuel cost and second fuel cost.

The method may also include receiving a signal from each LTO device indicating an amount of each fuel type available within the locomotive, wherein at least one locomotive includes an alternate fuel type, wherein the generated alternate throttle setting for each locomotive is based on equalizing an alternative fuel type consumption among the locomotives.

An advantage of the present subject matter is that it accommodates alternative fuels in a consist by adding a “fuel type” parameter in the locomotive configuration table for the throttle notch, power and fuel consumption.

In addition, the present subject matter revises substitution calculations by including a fuel type energy cost/value with the fuel type in the LTO locomotive configuration database.

By assigning the master LTO by update revision or date, the present subject matter always has the latest locomotive configurations in the master LTO and the latest relative fuel values. Accordingly, fleet wide LTO updates are never needed.

Yet another advantage of the present subject matter is that it accommodates more than one fuel type at a time in the consist. In addition, the present subject matter accommodates more than one engine operating mode in a dual fuel locomotive.

Another advantage is that the present subject matter interfaces with or incorporates an AESS for idle shut down.

Additional objects, advantages and novel features of the examples will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following description and the accompanying drawings or may be learned by production or operation of the examples. The objects and advantages of the concepts may be realized and attained by means of the methodologies, instrumentalities and combinations particularly pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawing figures depict one or more implementations in accord with the present concepts, by way of example only, not by way of limitations. In the figures, like reference numerals refer to the same or similar elements.

FIG. 1 is a is block diagram of a locomotive consist.

FIG. 2 is a table listing some locomotive parameters and sample alternate throttle settings.

FIG. 3 is a table of different locomotive consists with calculated benefits from using an LTO.

FIG. 4 is a schematic of an embodiment of the system disclosed herein including a controller in communication with a memory and a database.

DETAILED DESCRIPTION OF THE INVENTION

Alternate Fuel is defined as any fuel used in a locomotive that is not diesel fuel, examples include natural gas, hydrogen, ethanol, propane or Dimethyl Ether.

Dual Fuel locomotive is defined as a locomotive that can operate at rated power on different fuels at different times. Typically this is a locomotive that will operate on 100% diesel and then when natural gas is available it will substitute as much natural gas for diesel fuel as the engine will tolerate. In well-developed conversions, the amount of diesel fuel could be reduced to 5% or 10% that acts to pilot ignite the main natural gas charge. A dual fuel locomotive may also use another alternative fuel such as hydrogen or cellulosic ethanol as a primary fuel with a small amount of diesel fuel as a pilot for ignition.

In the following detailed description, a plurality of specific details, such as specific signals used for multiple locomotive control in a consist and exemplary fuel burn rates and efficiency calculations, are set forth in order to provide a thorough understanding of the preferred embodiments discussed below. The details discussed in connection with the preferred embodiments should not be understood to limit the present invention.

FIG. 1 is a block diagram of a locomotive consist 10. The consist 10 includes a plurality of dual fuel locomotives 110, LNG tender 115, and locomotives 100. Each locomotive 100 is provided with a Locomotive Throttle Optimizer (LTO) device 200 and each dual fuel locomotive 110 is provided with an LTO device 210. An MU jumper 199 electrically connects the locomotives 100, dual fuel locomotives 110 and LNG tender car 115 together in a MU consist. At the present time, the standard MU jumper includes 27 conductors. Preferred embodiments of the invention make use of conductors included on standard MU jumpers 199 for communications between all of the LTO devices 200 and LTO devices 210. Although the LNG Tender does not have an LTO device installed it may have an MU jumper 199 at each end to pass the MU train line power and signals through it to the rail vehicles adjacent to it on each end. In alternative embodiments, additional conductors (which may be included in the MU jumpers 199 or may be provided via physically separate cables) may be added for such inter-locomotive communications, or wireless communications may be used instead. It should further be recognized that additional cars (e.g., freight cars) may also be present in consists and that such non-locomotive vehicles may be interposed between locomotives in the consist (such consists are sometimes referred to as distributed power consists).

Although each locomotive 100 includes an LTO device 200 and each dual fuel locomotive 110 includes an LTO device 210 in the consist 10 of FIG. 1, it should be understood that it is possible for some of the locomotives in the consist not to be equipped with an LTO device in some embodiments. In such embodiments, the engine control signals on those locomotives not equipped with an LTO device may be electrically connected to the signals on the MU jumper corresponding to the throttle position set on the lead locomotive in the conventional manner. In other words, if a locomotive in the consist 10 does not have an installed LTO device, that locomotive will be controlled in accordance with the notch selected by the operator in the lead locomotive.

Traditional LTO devices are equipped with locomotive configuration data tables for each available locomotive configuration that at a minimum incorporates the power produced and the fuel consumed at each throttle notch. LTO device 210 is a new embodiment of the LTO device concept for use with alternative fuel and dual fuel locomotives. Because of this the locomotive configuration tables also need to incorporate a fuel type parameter and the relative energy cost of that fuel type. The LTO 210 locomotive configuration tables will need to accommodate the dual fuel nature of the dual fuel locomotive with a table for each possible operating mode. In one operating mode it may run on 100% diesel fuel so it will only need the basic table with power and fuel consumption for each notch. If there is an additional dual fuel operating mode with multiple fuels, the LTO device 210 will need to have additional tables. These additional multi fuel tables will still have a single power value for each throttle notch, but will also have to incorporate a fuel consumption value for each fuel consumed at that throttle notch. It will also need parameters to indicate the particular fuel types being consumed and their energy costs compared to diesel fuel. There also should be a parameter set for what operating mode the particular locomotive is currently operating at and this parameter needs to be communicated to the Master LTO if it changes. In some instances a dual fuel locomotive 110 that was operating in dual fuel mode consuming a mixture of natural gas and diesel fuel could no longer have an available supply of natural gas fuel. In this instance the master LTO device that is calculating the alternative throttle settings should be aware that this particular dual fuel locomotive is no longer consuming natural gas. This should initiate a new set of calculations that may come up with different alternative throttle settings to consume more natural gas on other locomotives in the consist now that this dual fuel locomotive is consuming only diesel fuel.

LTO device 200 could be considered a basic LTO device as known in the prior art that would work on existing technology diesel fueled locomotives. In order to work with LTO devices 210 these LTO devices 200 would have to have a compatible communications protocol with the appropriate initialization information that a newer LTO device will be able to communicate with it, recognize it and issue it alternative throttle commands.

It is projected that dual fuel locomotives are only a transition technology as the railroad industry starts to use different alternative fuels. More stringent emissions regulations over time should make it impractical to have a locomotive consume multiple fuels at both low emissions and high efficiency. The current thought is that natural gas will replace diesel fuel for the next several decades, but as technology evolves the future alternative fuel could be some other gas or liquid fuel such as hydrogen or cellulosic ethanol.

Future locomotives that may run on a single fuel again may consume only natural gas or hydrogen. In this case the LTO device 200 will need one modification from the current prior art. It will need an identifier of what its fuel type is in addition to its minimal table of power and fuel consumption at each throttle notch. When the dual fuel LTO device 210's are first implemented, it may be the case that an LTO device 200 that does not have a fuel type parameter in its initialization string will be assumed to operate on 100% diesel fuel and only other types of fuel will need to be identified.

As there are over 20,000 locomotives in service in North America and most of them can operate in MU consists, the LTO concept is initially devised as an add-on control box that is incorporated into an existing locomotive. In other embodiments the LTO device can be incorporated into another add-on control box that is the basis for converting an existing diesel locomotive to operate on dual fuel. Further the features of the LTO system can be incorporated into the control systems of new locomotives.

FIG. 2 is a table of locomotive data. The first column indicates the typical throttle notches that locomotives are operated at with Notch 8 being full power that is incrementally reduced down to Notch 1, minimum tractive power, followed by both the Idle throttle notch and the Dynamic Brake throttle notch.

Column 2 is a representative duty cycle for a locomotive in linehaul freight service. Noticeable is that the locomotive spends most of its time in either idle or at Notch 8. Although the time spent at idle is over twice the time spent at Notch 8, at idle the locomotive consumes less than 2% of the Notch 8 fuel flow.

Column 3 is a sample breakdown of the engine power produced by a 4000 hp locomotive in the various throttle notch settings.

Column 4 is a sample list of diesel fuel substitution rates for an early dual fuel system on a 4 stroke GE locomotive. The trend in these numbers is typical for dual fuel natural gas conversion systems based on fumigating the intake on an unmodified diesel engine. The highest rate of substitution is at a lower throttle setting somewhere between ¼ and ½ load. As the power setting approaches full load the engine becomes sensitive to engine knocking and the substitution rate has to be reduced. Also as the engine operates at very low loads approaching idle, it operates so lean that it has trouble maintaining high enough cylinder temperatures to burn any natural gas that is injected. In this case, from Notch 2 down thru Dynamic Braking the engine runs on 100% diesel fuel. It is by avoiding 100% diesel operating in throttle notches 1 and 2 that the LTO systems offer the most value as it calculates and applies alternate throttle settings.

Column 5 is a sample list of diesel fuel substitution rates for a converted dual fuel EMD engine in a locomotive application. Unlike a fumigation based dual fuel system typically installed on a four stroke engine, this engine was significantly modified during the dual fuel conversion to have a very high substitution rate at full load. With improved aftercooling and a lowered compression ratio this engine can operate with up to 92% of the diesel fuel being displaced by natural gas. In this case the trend is that the gas substitution is highest at full load and drops steadily as engine load is reduced. This is because the two stroke engines on average operate leaner than four strokes and as the load is reduced the air to fuel ratio increases even further in these unthrottled engines. As seen in the four stroke engine, as the engine approaches Notch 2, the air fuel ratio is so high and combustion temperatures so low that the natural gas will not burn. As in the case of current locomotive four stroke fumigation system, the current dual fuel EMD engine system will operate from Notch 2 down thru dynamic brake on 100% diesel.

The additional columns in this chart illustrate the application of alternate throttle notches to a consist containing two dual fuel locomotives and one conventional diesel locomotive. Column 6 illustrates the power request from the train operating engineer. This is simply a function of multiplying the single locomotive power level at that throttle notch setting by the number of active locomotives in the consist. Column 7 is a sample list of applied power settings when the alternate throttle settings are applied. It illustrates that there will be a range of deviation that is allowed between what is requested by the engineer and what is applied. This deviation is likely to be 5% or less, and should be configurable in the design and setup of the LTO system. Because the throttle notch settings are discrete setting, it is unlikely to get an exact match of alternate throttle setting power and requested power.

Column 8 contains a sample of likely applied alternate throttle settings for the consist if the dual fuel locomotives were EMD locomotive. Because the natural gas substitution rate is highest at notch 8, it is apparent that the systems maintains at least one of the dual fuel locomotives in notch 8 whenever possible and commands the conventional diesel locomotive to operate at the lowest throttle setting possible, including idle.

Column 9 contains a sample of likely applied alternate throttle settings for the consist if the dual fuel locomotives are GE 4 strokes with fumigation dual fuel systems. Because the peak substitution rate happens at a lower throttle setting, the alternate throttle results are not the same as the EMD based system. It may be non intuitive, but the goal will be to keep as many of the dual fuel GE locomotives in Notch 7 as possible as that is where the highest amount of natural gas is consumed. It is not where the peak replacement rate is, but as the amount of natural gas consumed is a function of both the power produced and the rate of diesel substitution, in this example, Notch 7 is where the most natural gas is consumed. It is the purpose of these new LTO systems not to reduce the total amount of energy consumed, but to consume the highest proportion of the lowest cost fuel. This typically has the beneficial side effect of generating the lowest amount of criteria emissions and greenhouse gasses also. The trend in this column is to keep at least one dual fuel locomotive in notch 7 as long as possible, and then generate the most power possible with the pair of dual fuel locomotives.

In both the EMD and GE alternate throttle setting columns, the highest power setting was applied to the first of the dual fuel locomotives, this is only for example. It is likely the LTO system would alternate which dual fuel locomotive was at a higher power setting in order to either balance the wear and tear on the engine or the natural gas fuel consumption depending on the fuel storage type and quantity. Some future natural gas locomotives may use onboard natural gas storage and their fuel quantity will need to be considered as alternate throttle settings are calculated as a dedicated natural gas locomotive that runs out of fuel will not be able to apply power in a consist when the engineer has requested full power from all of the locomotives in the consist.

Although notch 8 is the throttle setting used predominantly while in operation pulling freight, almost twice as much time is spent in Notches 1 thru 6 where the diesel only locomotive is idling. An alternate embodiment of the LTO system could incorporate a signal that will initiate an idle shutdown of the locomotive least likely to be turned on until the engineer moves the throttle up past notch 6. If this consist had more than 1 conventional diesel locomotive in a consist with a pair of dual fuel units, this opportunity to shut down at least one diesel locomotive would occur for longer periods and more often. Although the fuel cost savings would not be that significant do to the low fuel consumption at idle, the emissions reductions would be substantial. Because of the colder combustion temperatures at idle, the hydrocarbon, CO and PM emissions of the locomotives are worst at idle. For this reason most locomotives have been equipped with automatic engine start stop (AESS) systems and during the implementation of an LTO system, this AESS system could be incorporated into the LTO system or the LTO system could incorporate an output that would signal to an external AESS system that it can stop idling as long as it is safe for the engine to do so. The AESS systems are designed to start up occasionally to keep the engines coolant warm, in this application they would allow the shut down engine to be brought back into service quickly if the engineer requested a power setting requiring the power from the shut down locomotive.

FIG. 3 is a table indicating some different consist configurations and the benefits of a possible LTO system in these configurations. The first column is the configuration of the consist listing the locomotives being used. ‘GE’ represents a conventional diesel powered locomotive whereas ‘DF.GE’ represents a typical dual fuel converted GE locomotive. ‘EMD’ represents a typical diesel powered EMD locomotive whereas ‘DF.EMD’ represents a typical dual fuel converted EMD locomotive. These consists are for example only as any combination of conventional and dual fuel locomotives could be combined with locomotives from either manufacturer.

The second column illustrates the diesel substitution rate for the consist without the use of an LTO system and the third column is an example of the diesel fuel substitution rate with a sample LTO system in operation. The fourth column is a calculation of how much the substitution rate was improved by the application of the LTO system and the last column is a calculation of how much in fuel cost is saved per year per locomotive with the addition of an LTO system to each locomotive.

Some interesting points from the table, without an LTO system, row 1 indicates that the basic substitution rate for a sample GE dual fuel locomotive is 41.29%, this means that 41.29% of the diesel fuel that would have been consumed has been replaced by natural gas on an energy content basis. When an LTO system is used, the substitution rate increases to 42.42%, which is almost a 3% improvement and nets a yearly fuel savings of $7,955 per locomotive which should be more than the cost of an LTO add on system. Below the table are the fuel cost and consumption values used to calculate these fuel savings numbers.

Row 2 is the same pair of dual fuel locomotives in a consist with an added single diesel powered locomotive. With the consist not using an LTO system the substitution rate of 41.29% for the pair drops to 23.95% for all three locomotives. When an LTO system is added the substitution rate jumps almost 20% to 28.64% and the yearly fuel savings jumps to $33,018 per locomotive which is over 6 times the predicted cost for the LTO device. The next row with a second diesel locomotive added to the consist continues the trend of improvement with a 30% increase in substitution rate and $37,664 in yearly fuel savings per locomotive.

Row 4 and down is a similar progression of consists but using EMD 2 stroke locomotives with a higher diesel fuel substitution rate. In Row 4 the EMD overall substitution rate is 78.30% showing the added value of the more extensive conversion process over the GE 4 stroke fumigated dual fuel locomotives at 41.29%. When the LTO system is added to a pair of dual fuel EMD locomotives, the substitution increase is also greater at a 4% increase in substitution, and because we were already substituting more diesel the increase is compounded in effectiveness and this system now saves almost 3 times as much in yearly fuel costs at $21,824 per locomotive.

In row 5, when two dual fuel EMD's are operated with a single diesel fueled locomotive the substitution rate again increases around 20% and yields a yearly fuel cost savings per locomotive of $74,624. The same trend as before is noticed when a fourth diesel fueled locomotive is added in row 6.

As mentioned above and shown in FIG. 4, aspects of the systems and methods described herein are controlled by one or more controllers 12. The one or more controllers 12 may be adapted to run a variety of application programs, access and store data, including accessing and storing data in the associated databases 16, and enable one or more interactions as described herein. Typically, the controller 12 is implemented by one or more programmable data processing devices. The hardware elements, operating systems, and programming languages of such devices are conventional in nature, and it is presumed that those skilled in the art are adequately familiar therewith.

For example, the one or more controllers 12 may be a PC based implementation of a central control processing system utilizing a central processing unit (CPU), memory 14 and an interconnect bus. The CPU may contain a single microprocessor, or it may contain a plurality of microprocessors for configuring the CPU as a multi-processor system. The memory 14 may include a main memory, such as a dynamic random access memory (DRAM) and cache, as well as a read only memory, such as a PROM, EPROM, FLASH-EPROM, or the like. The system may also include any form of volatile or non-volatile memory 14. In operation, the memory 14 stores at least portions of instructions for execution by the CPU and data for processing in accord with the executed instructions.

The one or more controllers 12 may also include one or more input/output interfaces for communications with one or more processing systems. Although not shown, one or more such interfaces may enable communications via a network, e.g., to enable sending and receiving instructions electronically. The communication links may be wired or wireless.

The one or more controllers 12 may further include appropriate input/output ports for interconnection with one or more output mechanisms (e.g., monitors, printers, touchscreens, motion-sensing input devices, etc.) and one or more input mechanisms (e.g., keyboards, mice, voice, touchscreens, bioelectric devices, magnetic readers, RFID readers, barcode readers, motion-sensing input devices, etc.) serving as one or more user interfaces 30 for the controller 12. For example, the one or more controllers 12 may include a graphics subsystem to drive the output mechanism. The links of the peripherals to the system may be wired connections or use wireless communications.

Although summarized above as a PC-type implementation, those skilled in the art will recognize that the one or more controllers 12 also encompasses systems such as host computers, servers, workstations, network terminals, and the like. Further one or more controllers 12 may be embodied in a device, such as a mobile electronic device, like a smartphone or tablet computer. In fact, the use of the term controller 12 is intended to represent a broad category of components that are well known in the art.

Hence aspects of the systems and methods provided herein encompass hardware and software for controlling the relevant functions. Software may take the form of code or executable instructions for causing a controller 12 or other programmable equipment to perform the relevant steps, where the code or instructions are carried by or otherwise embodied in a medium readable by the controller 12 or other machine. Instructions or code for implementing such operations may be in the form of computer instruction in any form (e.g., source code, object code, interpreted code, etc.) stored in or carried by any tangible readable medium.

As used herein, terms such as computer or machine “readable medium” refer to any medium that participates in providing instructions to a processor for execution. Such a medium may take many forms. Non-volatile storage media include, for example, optical or magnetic disks, such as any of the storage devices in any computer(s) shown in the drawings. Volatile storage media include dynamic memory, such as the memory 14 of such a computer platform. Common forms of computer-readable media therefore include for example: a floppy disk, a flexible disk, hard disk, magnetic tape, any other magnetic medium, a CD-ROM, DVD, any other optical medium, punch cards paper tape, any other physical medium with patterns of holes, a RAM, a PROM and EPROM, a FLASH-EPROM, any other memory chip or cartridge, or any other medium from which a controller 12 can read programming code and/or data. Many of these forms of computer readable media may be involved in carrying one or more sequences of one or more instructions to a processor for execution.

It should be noted that various changes and modifications to the embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. For example, various embodiments of the method and portable electronic device may be provided based on various combinations of the features and functions from the subject matter provided herein. 

We claim:
 1. A locomotive consist system comprising: at least two locomotives, wherein each locomotive includes a locomotive throttle optimizer (LTO), wherein at least one locomotive includes an alternate fuel type; wherein at least one LTO device is a master LTO device in communication with every other LTO device, wherein the master LTO device includes: a controller; and a memory coupled to the controller, wherein the memory is configured to store program instructions executable by the controller, wherein in response to executing the program instructions, the controller is configured to: receive an engineer throttle notch value corresponding to a total power value; access a database including locomotive information for each locomotive in the consist, wherein the locomotive information includes a fuel type used in the locomotive, a fuel consumption rate corresponding to each of a plurality of throttle notch power levels, and a fuel consumption priority parameter corresponding to each fuel type used in the locomotive; generate an alternate throttle setting for each locomotive, wherein the alternate throttle setting includes a selected throttle notch power level, wherein the combination of alternate throttle settings for the at least two locomotives produces a generated total power that is equivalent to the received total power value, wherein the alternate throttle setting is based on the fuel consumption priority parameter; and communicate the alternate throttle setting to each locomotive.
 2. The system of claim 1 wherein the fuel consumption priority parameter includes a fuel cost, wherein the controller is configured to calculate for each throttle notch power level a fuel consumption cost, wherein the alternate throttle setting is based on minimizing the total fuel cost.
 3. The system of claim 1 wherein the master LTO device receives a signal from each LTO device indicating an operating mode for the locomotive, wherein the operating mode is selected from a primary fuel mode or a dual fuel mode.
 4. The system of claim 1 wherein the master LTO is the LTO with the most recent software update.
 5. The system of claim 1 wherein at least one fuel type is diesel fuel.
 6. The system of claim 1 wherein at least one fuel type is natural gas.
 7. The system of claim 1 wherein at least one fuel type is a mixture of an alternative fuel type and a second fuel type.
 8. The system of claim 1 wherein at least one locomotive is a dual fuel locomotive including a first fuel type and a second fuel type; wherein the database includes a plurality of first fuel consumption rates of the first fuel type and a plurality of second fuel consumption rates of a second fuel type, wherein each first consumption rate corresponds to a first fuel power value and a first fuel cost and each second consumption rate correspond to a second fuel power value and a second fuel cost, wherein a total fuel cost is the sum of the first fuel cost and second fuel cost, wherein the controller generates an alternate throttle setting for the dual fuel locomotive including a selected first fuel consumption rate of the first fuel type and a selected second fuel consumption rate of the second fuel type, wherein the alternate throttle setting for the dual fuel locomotive is based on minimizing the total fuel cost.
 9. The system of claim 8 wherein the first fuel cost and second fuel cost are automatically and periodically updated to reflect the market price of the first fuel and second fuel.
 10. The system of claim 8 wherein the master LTO device receives a signal from each LTO device indicating an amount of each fuel type available within the locomotive, wherein at least one locomotive includes an alternate fuel type, wherein the generated alternate throttle setting for each locomotive is based on equalizing an alternative fuel type consumption among the locomotives.
 11. The system of claim 8 further comprising a single fuel locomotive including a single fuel type and a single fuel LTO device in communication with the single fuel locomotive, wherein the single fuel LTO device is in communication with the controller, wherein the database includes a plurality of single fuel consumption rates for the single fuel type, wherein each single fuel consumption rate corresponds to a single power value and a single fuel cost, wherein the controller generates an alternate throttle setting including a selected first fuel consumption rate of the first fuel type, a selected second fuel consumption rate of the second fuel type, and a selected single fuel consumption rate of the single fuel type, wherein the received total power value is equal to the sum of the first fuel power value of the selected first fuel consumption rate, the second fuel power value of the selected second fuel consumption rate, and the single fuel power value of the selected single fuel consumption rate, wherein a total fuel cost is the sum of the first fuel cost, second fuel cost, and the single fuel cost, wherein the alternate throttle setting is based on minimizing the total fuel cost.
 12. A method for producing alternate throttle setting for at least two locomotives in a consist, wherein each locomotive includes a locomotive throttle optimizer (LTO), the method comprising: receiving an engineer throttle notch value corresponding to a total power value; accessing a database including locomotive information for each locomotive in the consist, wherein the information includes a fuel type used in the locomotive, a fuel consumption rate corresponding to each of a plurality of throttle notch power levels, and a fuel consumption priority parameter corresponding to each fuel type used in the locomotive; generating an alternate throttle setting for each locomotive, wherein the alternate throttle setting includes a selected throttle notch power level, wherein the combination of alternate throttle settings produces a generated total power that is equivalent to the received total power value, wherein the alternate throttle setting is based on the fuel consumption priority parameter; and communicating the alternate throttle setting to each locomotive.
 13. The method of claim 12 wherein the fuel consumption priority parameter includes a fuel cost, wherein the method includes calculating for each throttle notch power level a fuel consumption cost, wherein the alternate throttle setting is based on minimizing the total fuel cost.
 14. The method of claim 12 further including receiving a signal from each LTO device indicating whether each LTO is operating in a primary fuel mode or dual fuel mode.
 15. The method of claim 12 wherein at least one fuel type is diesel fuel.
 16. The method of claim 12 wherein at least one fuel type is natural gas.
 17. The method of claim 12 wherein the at least one fuel type is a mixture of an alternative fuel type and a second fuel type.
 18. The method of claim 12 wherein at least one locomotive is a dual fuel locomotive including a first fuel type and a second fuel type; wherein the database includes a plurality of first fuel consumption rates of the first fuel type and a plurality of second fuel consumption rates of a second fuel type, wherein each first consumption rate corresponds to a first fuel power value and a first fuel cost and each second consumption rate correspond to a second fuel power value and a second fuel cost, wherein a total fuel cost is the sum of the first fuel cost and second fuel cost, wherein the method includes generating an alternate throttle setting for the dual fuel locomotive including a selected first fuel consumption rate of the first fuel type and a selected second fuel consumption rate of the second fuel type, wherein the alternate throttle setting for the dual fuel locomotive is based on minimizing the total fuel cost.
 19. The method of claim 18 further including automatically and periodically updating the first fuel cost and second fuel cost to reflect the market price of the first fuel cost and second fuel cost.
 20. The method of claim 18 further including receiving a signal from each LTO device indicating an amount of each fuel type available within the locomotive, wherein at least one locomotive includes an alternate fuel type, wherein the generated alternate throttle setting for each locomotive is based on equalizing an alternative fuel type consumption among the locomotives. 